Shade Tree Sanding Tools and Bargain Paper

Wed Aug 15, 2007 3:13 pm

Shade Tree Sanding Tools and SandpaperHaving enough of the right sandpaper on hand is a balancing act. The most econominal way to buy sheets is in a sleeve of 50 or 100 sheets. But there are a couple of constraints to having a boatload of sandpaper around. One is that you could have several hundred dollars tied up in sandpaper. Another is that paper-backed sandpaper is sensitive to humidity. It will tend to curl when left in the sleeve in a non-air conditioned shop. This curl can make it difficult use the sandpaper. In addition, the humidity can soften the glue that holds the grit onto the paper. And sandpaper with no sand is just expensive paper. Here are some things that I have found to be useful in addition to the sleeves of sheet sandpaper that I have on hand.

20# Box of End RollsWhen it is time to do a little sanding, I first turn to my box of end rolls from Klingspor's WoodWorking Shop. These are the ends of large rolls that would otherwise be scrapped. When the box arrives it is kinda' like Christmas since there is no way to know exactly what I will find. In the past, I've had a pretty good mix of grits with lots of 220 and other grits ranging from 80 to 500. The width of the rolls can vary from 1" to 4" and each roll is 15' to 25' long. The 400 and 500 rolls were narrow while the rest was in the range of 2 1/2" to 3". However, each roll is a constant width. You are not going to see a roll that tapers from 1" to 3". The sandpaper is cloth-backed rather than paper-backed so the humidity/glue problem does not come into play. I find these rolls most useful for lathe work but they are also handy for small and difficult to sand areas. Anybody can sand a large flat area with sheets, but getting into small areas or crevises is more difficult with 1/4 sheets. I rip a piece off a roll and get after it. Sometimes, I'll use a hemostat/clamp to grab the sandpaper to get into tight areas.

5# Box of Adhesive End RollsAnother Klingspor deal is the box of adhesive rolls. Just like the plain bargain box, except sticky on the back. Why would you need sticky? You can use just about anything as a sanding block with sticky sandpaper. Need to sand a groove that is 3/8" radius? Grab a piece of old garden hose, stick a piece of sandpaper to the hose and go for it.

Sandpaper PressIf you have sheets of sandpaper and live in a humid climate, consider making a sandpaper press. Sheets are nominally 9"x11", so I cut a couple of pieces of 3/8" plywood 11"x14" to use as the press sides. The press action is accomplished by 4 pieces of 1/4-20 threaded rod used to bolt the press sides together. To make access easier, I used T-nuts on one panel and brazed wingnuts to the threaded rod for the bolts.

I had some old cheap plastic 3 ring binders and cut the covers off to make separators to go between different grits. These separators were punched on one edge so they stay attached to the lower set of press bolts. To use the press, loosen a pair of the press bolts and the press will open like a book. Pull out the sheets you need and reassemble the press. Here are some pictures of the sandpaper press, both closed up and open.

Custom Hard Rubber Sanding Blocks

The standard hard rubber sanding block is designed for 1/4 sheets of sandpaper. These blocks can be found at auto supply places like AutoZone or Napa, Autobody Paint suppliers, and even at Harbor Freight. The best price I found was Harbor Freight for about $2 each. But what if you need to sand an area where the sanding block won't fit? My solution was to buy a couple of extra blocks and cut them into narrower sizes. I used a bandsaw, but this could also be done with a hacksaw. Once the blocks were cut, I cleaned up the edges with a belt sander. They finish up quite nicely. The original reason I made smaller blocks was to take advantage of the 20# Box of End Rolls. All of the 220 grit in my box was about 2 1/2 inches wide, so I made a block that width. By coincidence, I had a 1" block leftover. The 1" block has proven very handy for sanding hard to reach places. The first photo is the standard 1/4 sheet block and a long 1/2 sheet block.

Here are some of the smaller sanding blocks made from 1/4 sheet blocks. Notice the block for the Bargain Box 220 is marked so I know which one to grab.

Other Sanding Tools

In addition to the standard hard rubber sanding block, there are other sanding "blocks" for other sizes of paper. There are also blocks that take standard Peel & Stick abrasives (PSA). For instance, here is a block for 6" round PSA sheets that is available from Eastwood.

For regular sheet sandpaper, there are longer blocks that take a 1/4 or 1/3 sheet using the full length of the paper. This allows you to get a flatter finish than you'll get when using a smaller block. A longer block will bridge surface variation allowing you to see high and low spots better. A small block will ride up and down in the low spots making eveything LOOK like it is flat. But if you step back and look along the surface, you can see the surface variation. Using a longer block tends to reduce these highs and lows. Here is a longer block that I got from Harbor Freight.

Porter-Cable made a detail sander that uses individual rubber blocks in different profiles. You can either get the sander and use these blocks that way, or just get the blocks and use them by hand. There are convex, concave, flat, and knife edge Profile Sanding Blocks. I got a bunch of them when Furrow's was closing out. But I expect they are still available if you look around. Here is a selection of the profile blocks I have.

But you are not limited to "store-bought" sanding blocks. Almost anything can be used as a sanding block. A piece of garden hose will give you nice fillets. The handle of an old toothbrush allows you to get into small places for detail work. If you need a particular shape, use Bondo. For instance, if you wanted to make a sanding block to work in between the ridges on the Cub's hood, lay a piece of plastic kitchen wrap over the ridges. Mix up some Bondo and spread it over the plastic in the area you want to duplicate. Before the Bondo cures, press a wood block into the Bondo. Once everything cures, pull the block away from the original and remove the plastic wrap. You will now have a custom formed sanding block. Wrap some thin sandpaper around the block and start sanding. As you press the block down, the sandpaper will fold/bend to fit between the sanding block and the original surface. Here are some things I use as sanding blocks. In all 3 of these, I've used PSA paper from Klingspor's Bargain Box.

UPDATE: Another use for the $0 epoxy applicatorI was trying to clean out a narrow slot was could not get enough pressure on the sandpaper to actually do any work. I remembered a thread about using plastic cards as epoxy spreaders. Well, the same plastic card makes a fine sanding block. Wrap a piece of sandpaper around it or use a piece of PSA paper and get to it. It is stiff enough to allow some sanding to take place, but flexible enough that it will conform to slight curves.

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